Situated on top of Number 7 Hanger, presently utilised by the Zwartkop Fire Section, is the oldest Watch Tower / Control Tower in the Southern Hemisphere. The Watch Tower was erected here in 1927 when, in the interests of flying safety, a requirement was identified to exercise some sort of control over all the flying activities at the Air Station.

 Long before the use of radio’s, aircraft at this airfield were controlled by using Aldis signaling lamps, verey cartridge flares, semaphore flags and various other signaling devices. The black and white signal balls indicated to pilots whether flying was authorized or not. If the white ball was hoisted, flying was on for the day. If the black ball was hoisted, flying was cancelled or postponed for reasons such as inclement weather, high wind speeds or decisions made by Higher Authority.

The Watch Tower / Control Tower was normally manned on a daily basis by Pilots who were grounded due to medical or other reasons. The manning of this Tower was also used as an effective discipline deterrent for young pupil pilots to mend their ways and maintain an acceptable standard of military bearing and discipline. Manning this Tower during a severe Highveld winter would not have been a pleasant experience.

When radio communication was introduced, a qualified Signals Non-Commissioned Officer would also sit in the Tower to assist the Airfield Controller. The Watch Tower fell into disuse in 1941 when a completely new Headquarters and Control Tower were built in 1940 by 24 Group Royal Air Force, the Controlling Authority of Zwartkop Air Station at the time.

The Watch Tower / Control Tower later became derelict and the wood planking, originally from aircraft packing crates, rotted away. Various attempts were made during the 1980’s to restore the feature but it was only during the early 2000’s, that a team from Air Force Base Zwartkop, led by Colonel Itel Zurich, carried out a complete restoration of the Watch Tower itself. The rusted and damaged access ladder was also replaced in its entirety, returning the Watch Tower to its former glory.

watermarked-Control Tower 1920.jpg|Watch Tower / Control Tower with Signal Balls in Place

 watermarked-Watch Tower on Hanger 7.jpg|Control Tower on Top on Number 7 Hanger